Free webp to jpg
EN
Image MIME Reference
CMU-Raster

CMU Window Manager Raster

image/x-cmu-raster
VS

Network FlashPix

image/vnd.net-fpx
Net-FPX

A complete technical comparison of CMU Window Manager Raster and Network FlashPix — covering compression, feature support, browser compatibility, magic bytes, and when to choose each format.

Equal browser support

Feature Support

Feature CMU-Raster Net-FPX
Transparency (Alpha) ✕ No Yes
Animation Support ✕ No ✕ No
Progressive Loading ✕ No Yes
HDR Support ✕ No ✕ No
EXIF Metadata ✕ No Yes
ICC Color Profile ✕ No Yes
CMU Window Manager Raster
image/x-cmu-raster
Extension
.ras
Container CMU Window Manager Bitmap
Compression Uncompressed
Algorithm
None
Color Depth 1-bit (Monochrome), 8-bit (Indexed/Grayscale)
Developed by Carnegie Mellon University (CMU)
Released 1980s
Magic Bytes
F1 00 40 BB
Full CMU-Raster reference →
Network FlashPix
image/vnd.net-fpx
Extension
.fpx
Container Microsoft OLE Structured Storage (COM)
Compression JPEG (Lossy) / Uncompressed / Single-color (Solid)
Algorithm
JPEGNone
Color Depth 8-bit (Grayscale/Indexed), 24-bit (RGB), 32-bit (CMYK/RGBA)
Developed by Digital Imaging Group (Kodak, HP, Live Picture, Microsoft)
Released 1996
Magic Bytes
D0 CF 11 E0 A1 B1 1A E1
Full Net-FPX reference →

Browser Support Comparison

Browser CMU-Raster Net-FPX
Chrome Chrome
✕ ✕
Firefox Firefox
✕ ✕
Safari Safari
✕ ✕
Edge Edge
✕ ✕
IE IE (Legacy)
✕ ✕
CMU-Raster

CMU-Raster Strengths

  • Incredibly simple, uncompressed binary structure that was easy for early, memory-constrained UNIX workstations to parse and render
Limitations
  • Completely obsolete and unsupported outside of niche historical command-line tools like Netpbm
  • The shared '.ras' file extension causes frequent file misidentification and system conflicts
  • Lacks all modern imaging features, including metadata, compression, and alpha channel transparency
Net-FPX

Net-FPX Strengths

  • Revolutionized web imaging in the late 1990s by proving that massive gigapixel images could be navigated seamlessly over 56k dial-up modems
  • Pioneered the tile-based, multi-resolution pyramid concepts that eventually evolved into modern standards like IIIF (International Image Interoperability Framework)
Limitations
  • Completely obsolete, having been replaced by standard JPEG servers and modern tiling formats like Deep Zoom or JPEG 2000/XR
  • Relied on proprietary Java applets or ActiveX controls to render the tiles dynamically in a web browser
  • Extremely complex to parse server-side due to the heavy OLE filesystem container

When to choose which format

CMU-Raster
Use CMU-Raster when…
  • Historical UNIX / Andrew Project Archival
  • Legacy Academic Computing Research
Net-FPX
Use Net-FPX when…
  • Historical Internet Imaging Protocol (IIP) Streaming
  • Early E-Commerce Deep Zoom Implementations
  • Legacy High-Resolution Image Servers

More comparisons

CMU-Raster vs ACES → Net-FPX vs ACES → CMU-Raster vs APNG → Net-FPX vs APNG → CMU-Raster vs AVCI → Net-FPX vs AVCI → CMU-Raster vs AVCS → Net-FPX vs AVCS → CMU-Raster vs AVIF → Net-FPX vs AVIF → All comparisons →
Share this comparison